On 03/05/2013 08:13 AM, Riccardo Veraldi wrote: > I managed to make ipsec-tools work on CentOS 6.x > here is how I did it: Yes, you got a tunnel working between two systems both running ipsec-tools on Linux. Try to link with anything else. The configuration that you present will not work with Openswan on Linux, ipsecctl on OpenBSD, Cisco or Sonicwall firewalls. Whatever your feelings about those other stacks, ipsec-tools use on Red Hat remains poorly documented (non-existent since the package was discontinued) and not inter-operable without undocumented options.